Short-range diversity and invasion dynamics of the freshwater jellyfish Craspedacusta sowerbii in Lake Kinneret, Israel, and its watershed: field sampling combined with hydrodynamical simulations

Dehos, Stefan; Amitai, Yael; Kuplik, Zafrir; Sussholz, Noy; Gießler, Sabine; Stibor, Herwig; Heifetz, Eyal (2026): Short-range diversity and invasion dynamics of the freshwater jellyfish Craspedacusta sowerbii in Lake Kinneret, Israel, and its watershed: field sampling combined with hydrodynamical simulations. NeoBiota, 107. pp. 309-329. ISSN 1619-0033

Abstract

The hydrozoan Craspedacusta sowerbii, native to the Yangtze River system in China, has become an invasive species in freshwater ecosystems worldwide. Multiple genetic lineages have been introduced globally, yet the species’ taxonomic identity has not been comprehensively resolved. The species life cycle alternates between a benthic polyp stage and a pelagic medusa stage, the latter being the primary focus of most distributional studies. In Israel, the species was previously reported from the Lake Kinneret watershed, though recent records are lacking. Here, we surveyed streams and ponds in the Golan Heights for both medusae and polyps and conducted genetic analyses on collected specimens. Three distinct cytochrome c oxidase subunit I (COI) haplotypes were identified, corresponding to those previously described from European and Asian populations. Most sites exhibited homogeneous COI haplotype composition, apart from a single site where different COI haplotypes co-occurred. This pattern suggests restricted short-distance dispersal and exchange, consistent with multiple independent colonization events. While our survey did not confirm the presence of C. sowerbii in its pelagic stage, the detection of polyps in multiple inflowing streams suggests that colonization of Lake Kinneret itself is likely in the future. To facilitate a proper monitoring program, we simulated the movement and distribution of possible medusae aggregations, originating from the inflowing Jordan River as well as from all surrounding shorelines of the lake. We first conducted 3D hydrodynamic simulations of the lake, incorporating the transport of medusae released from the main inflowing streams. The simulations suggest specific positions for coastal ‘hotspots’ of medusae distributions appearing yearly or seasonally. Furthermore, the simulations indicate seasonal variations in the penetration potential of medusae into the lake. In winter, they would penetrate deeper and away from the coasts, whereas in summer they are likely to remain concentrated near the lake surface and close to the coasts.

• Dokumententyp: Artikel (LMU)
• Organisationseinheit (Fakultäten): 19 Biologie > Department Biologie II
• DFG-Fachsystematik der Wissenschaftsbereiche: Naturwissenschaften